The liver is the single organ that is largest in the body and is said to have more than one hundred different kinds of functions including, in addition to metabolism of carbohydrates, lipids, proteins and amino acids, bile production, detoxication, foreign matter treatment, control of hormones, production of prothrombin, one of blood coagulating agents, storage of various constituents of organisms (such as fat, glycogen, proteins, vitamines, etc.) and the like. This organ which has such precise and well-balanced functions possesses a large self-restorative ability and hence is expected to heal spontaneously even if it is functionally disordered. Nevertheless the liver may suffer an acute or chronic lesion due to one or more of various factors such as alcohol, undernutrition, virus infection, medicaments, poisons, biliary obstruction, disorder of the enterohepatic circulatory system and the like and such lesion is manifested as one or more of diseases such as fatty liver, drug-toxic hepatic failure, drug-hypersensitive hepatic failure, alcoholic hepatitis, viral hepatitis, congestive hepatitis, hepatopathy due to biliary engorgement, jaundice, and hepatocirrhosis which is the final picture of the foregoing diseases.
When these hepatic failures are induced, a medication can be employed with the intention of accelerating restoration of cells of the liver parenchyma or alleviating the damage of liver cells with the aid of protection against various hepatopathy-inducing factors, thereby accelerating the recovery from its functional disorder or preventing aggravation.
The inventors have found that paticular cysteine derivatives are effective for the above-mentioned purpose and accomplished the present invention.